1. Field of the Invention
The invention relates to a character input technology, and more particularly to a technology for entering characters by using a keyboard.
2. Description of the Related Art
Among input devices for issuing predetermined instructions to a computer is a keyboard. In general, a keyboard has a plurality of keys, and a single character is assigned to each of the keys. Such a keyboard is considered to be a direct extension of a typewriter, having at least 26 keys to enter 26 alphabetical characters, for example. When a single character is thus assigned to each single key, the large number of keys makes it difficult to remember the key layout. Touch typing has thus required considerable time to learn. Moreover, the keyboard is large in size and inconvenient to carry. In view of this, there have been proposed keyboards which allow character input with fewer keys (Japanese Patent Laid-Open Publications Nos. Hei 7-200120 and Sho 60-231253).
Recently, with the development of network technologies, the numbers of users who, for example, use emails and access websites are increasing sharply. Even for users who have had nothing to do with keyboards so far, the chances to use keyboards to enter characters are on the increase accordingly. In addition, using a keyboard becomes increasingly inevitable in information society, and there are growing needs for input means that are friendly to all people.